Police want to speak to two men seen on mountain bikes close to Labour Party premises shortly before they was set alight.

The wilful act committed on Sunday night at 9.50pm is estimated to have caused thousands of pounds worth of damage to the building in Poplar Road, within Broadmeadow Industrial Estate.

Officers issued a statement this afternoon condemning the crime and earlier told how they were looking at all causes including links to the outcome of the Scottish independence referendum last week.

Detective Inspector David Moran of Clydebank CID, is leading the inquiry. He said: “Setting this fire was utterly irresponsible, reckless and very dangerous. Thankfully there was no one in the office at the time of the fire, however, the office was very badly damaged with a bill that will no doubt run into thousands of pounds to repair.

“There are also a number of other small businesses in the area which could have suffered if the fire had taken hold.

“I am particularly keen to speak to or identify two men seen riding mountain bikes in the area about 30 minutes prior to the fire being discovered and who may have important information. Additionally I would ask that anyone who has any information about the persons responsible for setting this fire to make contact with us."

Information about the fire can be given to officers via 101 or in confidence to Crimestoppers on 0800 555 111.